Sling jig assembly for use in loading and transporting bagged and bundled products

ABSTRACT

A method for loading a sling having a bottom and sidewalls comprises placing the sling bottom on a raised platform and rolling the sidewalls down into a gutter surrounding the raised platform so that the sidewalls form a negative angle with the sling bottom. Bagged product is then loaded onto the bottom of the sling to form a stack. The sling sidewalls are then rolled up the sidewalls up the stack sides so that the sidewalls form a positive angle with the sling bottom and the sling now encloses the stack of product. The sling jig assembly includes a raised central platform on which is adapted to rest the bottom of the sling. A gutter formed about the periphery of the central platform is adapted to receive the rolled-down sidewalls of the sling.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 11/424,496, which itself claims the benefit from U.S.Provisional Patent Application No. 60/692,385 filed Jun. 20, 2005 whosecontents are incorporated herein for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to containment systems and moreparticularly to methods and apparatuses for facilitating the loadingoperation of a sling device for use with transporting bagged or bundledgoods.

2. Description of the Prior Art

Granulated products such as seed, fertilizer, grains, and the like aretypically contained in nylon, cotton, burlap or plastic bags. Whentransporting mass quantities of such bags, the individual bags arestacked on pallets and lifted from below by forklift from place toplace. When such products are shipped for export on a vessel, however,it is more common to stack such bags 100 within a soft-sided sling asshown in FIG. 1. Such a sling would fully envelop bags 100, therebypreventing them from sliding from the stack when moved.

The sling includes a soft-sided outer bag 10 having a bottom 11 andsidewalls 13, conventionally formed from a strong fabric such as nylon.Surrounding the bag 10 are a web of support straps, such as supportstraps. The particular sling embodiment shown in FIG. 1 includes twostraps on each vertical sidewall 13 of the sling bag 10, such as straps12 a, 12 b along a facing sidewall of the bag and straps 12 c and 12 dalong left and right sidewalls respectively. Strap guides 14 a-14 dreceive straps 12 a-12 d, respectively, and wrap around the periphery ofand especially underneath the bag 10. The straps 12 a through 12 dconnect together over the top of bag 10 so that forklift forks 16 a, 16b can be received within the gap 18 formed beneath the straps.

The traditional method for loading bags 100 within the sling is by hand.The sling is laid flat on a floor and workers would lift each bag orbundle from an unload point and place them within the sling. Once thesling is filled with stacked bags 100 as shown in FIG. 1, a forklift oroverhead crane would lift the loaded sling by straps 12 a-12 d therebycausing the straps to cinch the sling closed. The act of individuallymoving bags to within the sling interior is extremely time intensive.

Accordingly, it is desired to provide a new process for loading baggedor bundled products within a sling for transport.

SUMMARY OF THE INVENTION

The apparatus uses a robotic arm to pick and place individual bags ofmaterial as they present themselves at the pick-up position on anin-feed conveyor belt. The bags are placed on an inside, bottom surfaceof a sling bag whose sidewalls have been rolled down. The sling bag sitsatop a sling jig assembly that includes a raised central platform onwhich the sling bottom sits, and a gutter surrounding the platform intowhich the sling sidewalls are rolled down into. The jig further has anunderside support structure that is adapted to sit on a conveyor belt.

In use, the jig is fitted with a sling by placing the sling bottom onthe raised jig platform and rolling the sling sidewalls down into thegutter. The jig is placed on a load conveyor and rolled into place in aload position adjacent the robotic arm. The robotic arm moves individualbags from the pickup position to the load position and places the bagsin preprogrammed orientations on the sling bottom and jig platform. Oncethe bags have been stacked in rows on the platform, the sling sidewallsare rolled upward over the sides of the stack of bags and attachedtogether at the top of the stack to form an enclosed bag. The loaded jigis then moved by the conveyor to an unload position where a forklift orrods of an overhead crane are passed through lifting straps on thesling. The sling is then lifted from the jig and moved to its storedposition in a warehouse for future loading onto a ship (e.g. the hold ofa cargo ship). The jig is then fitted with another sling and then movedvia the load conveyor back to the load position where the load andunload steps are again performed.

The foregoing and other objects, features and advantages of theinvention will become more readily apparent from the following detaileddescription of a preferred embodiment of the invention that proceedswith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a sling loaded with bagged product.

FIG. 2 is a perspective view of a sling jig assembly constructedaccording to a preferred embodiment of the invention.

FIG. 3 is a plan view of the sling jig assembly of FIG. 2.

FIG. 4 is a side elevation view of the sling jig assembly of FIG. 2shown along a long side of the jig.

FIG. 5 is a side elevation view of the sling jig assembly of FIG. 2shown along a short side of the jig.

FIG. 6 is a perspective view of a load/unload assembly environment inwhich the sling jig assembly of FIG. 2 is used.

FIG. 7 is a sectioned view of the sling jig, taken along lines 7-7 ofFIG. 3 with a sling bag mounted therein and product unloaded thereon.

DETAILED DESCRIPTION

FIG. 2 shows a preferred embodiment of a sling jig assembly at 20 inperspective view. FIGS. 3-5 show top, front, and side viewsrespectively.

Jig 20 is constructed to include an outer rectangular skirt 22 in whichthe four peripheral edges of skirt 22 are bent upward to form theflanges 24 a-24 d. Flanges 24 a-24 d are coupled together to adjacentflanges using metal ties, for instance metal tie 26 coupling flange 24 bto flange 24 c in FIG. 2 and coupling flange 24 a and 24 b in FIG. 3.The metal ties are affixed to the flanges via a set of bolts 27.

A raised platform 28 is placed on top of skirt 22 and between flanges 24a-24 d. Platform 28 includes sidewalls 30 defining a rectangularperiphery of platform 28 and having a raised platform top surface 32that projects above a bottom surface formed within skirt 22. Thesidewalls 30 of the raised platform 28 and the flanges 24 a-24 d of theskirt 22 form a trough or gutter 33 therebetween that runs about theperiphery of raised platform 32.

A preferred embodiment of the jig 20 includes an array of apertures 34formed through top surface 32 to allow air to escape as the sling isplaced on the jig. Metal support struts 35 (shown in dashed lines inFIG. 3) are fixed beneath top surface 32 to increase the strength of thejig assembly. A support structure affixed to an underside of the jigcomprises sets of support beams 38 and 36 running perpendicular to oneanother. Beams 38, positioned on each side of beams 36 to form a boxtherewith, extend below a bottom surface of beams 36 and are adapted tocontact and sit on a conveyor, such as load conveyor 52 shown in FIG. 6.At set of spaced apertures 39 are formed through beams 38 to act asforklift pockets for side access and lifting of jig 20 by forklift means56.

In operation, and as shown in FIGS. 6 and 7, a sling 10 is positionedwithin the jig 20 so that the sling bottom 11 and portions of the straps12 sit atop the jig raised platform 28. The sling sidewalls 13 are thenrolled down into the gutter 33 surrounding the raised platform 28 sothat the sling sidewalls 13 make a negative angle (that is, anglingdownward) from the sling bottom 11. In this way, the sling bag is almostinside out. Bagged products 100 are then placed atop the sling bottom 11with the sidewalls 13 rolled out of the way and not interfering withplacement of the bagged product within the sling. Once loading iscompleted, the sling sidewalls 13 are rolled up over the sides of thestacked product and enclose the stack. The straps 12 of the sling arethen coupled together to allow a forklift or overhead crane to move theloaded sling to another location.

FIG. 6 is a plan view of a load/unload assembly environment in which thesling jig assembly of FIG. 2 is used. The environment includes anin-feed conveyor 40 for transporting bagged products 100 serially to anunload position 42. A robotic arm 44, having an end effector orload/unload head 46 attached to a base 48 through a series of pivotedarms, engages with a bagged product at the unload position 42 wherebythe load/unload head 46 of the robotic arm clamps on, thereby engagingbagged product 100. The engaged bag is then moved to a load positionwithin the sling 10 mounted on the sling jig 20. Logic controls withinthe robotic arm are programmed to move between unload and loadpositions, with the load position changing with each successive pickupand placement depending upon where the next bagged product is to beplaced on the stack.

Once loading is complete, the sling bag 10 can be rolled up over thestack as described above to form a wrapped bundle 50. The sling jig 20and bundle 50 are then moved by load conveyor 52 for transport to anunload position 54. From the unload position, the loaded sling bag 10 islifted from the jig 20 and moved for further transport, as viaengagement of the tines 16a, 16b of forklift 56 shown in FIG. 6 with thestraps 12 passing over the bundle 50 to create a webbing, to asubsequent shipping position 60. The unloaded jig 20 is then moved backinto place at the load position, or a new jig put in its place toreceive further bagged product from the in- feed conveyor 40 via roboticarm 44.

Having described and illustrated the principles of the invention in apreferred embodiment thereof, it should be apparent that the inventioncan be modified in arrangement and detail without departing from suchprinciples. We claim all modifications and variation coming within thespirit and scope of the following claims.

1. A sling and jig assembly comprising: a rectangular skirt havingupturned peripheral edges and forming a cavity therein; a raised centralplatform having sidewalls and an elevated top surface located within thecavity between the peripheral edges of the skirt; a gutter formed withinthe rectangular skirt between the central platform sidewalls andupturned peripheral edges; and a sling having a bottom surface andstraps passing underneath the bottom surface resting on the elevated topsurface of the raised central platform, said sling further havingsidewalls rolled down into the gutter.
 2. The sling jig of claim 1,further including an underside support structure adapted to sit on aconveyor.
 3. The sling jig of claim 2, wherein said underside supportstructure includes metal support struts fixed beneath a top surface ofthe raised central platform adapted to increase the strength of the jigassembly.
 4. The sling jig of claim 3, wherein the underside supportstructure further comprises support beams.
 5. The sling jig of claim 1,further including an array of apertures formed through a top surface ofthe raised central platform adapted to allow air to escape as the slingbottom is placed on the jig.